use the right Notification Facades

app/Http/Controllers/TasksController.php

@@ -7,7 +7,7 @@ use App\Notifications\TaskDeleted;
 use App\Notifications\VolunteerAssignedToTask;
 use App\Notifications\VolunteerUnassignedFromTask;
 use App\Models\Event;
-use App\Models\Notification;
+use Illuminate\Support\Facades\Notification;
 use App\Models\Task;
 use App\Models\User;
 use Carbon\Carbon;